Observations

Description

Valves are lanceolate with broadly rounded and unprotracted or very weakly protracted apices. A longitudinal line is evident along each margin. The axial area is straight, about three times wider than the raphe, becoming somewhat wider near the central area. The central area is wide, rectangular in shape and crosses the valve diagonally. It is bordered by short faint striae along the valve margins. The raphe is lateral, becoming filiform at the proximal ends, which are hooked sharply in opposite directions. Striae are oriented diagonally across the valve face. Areolae number 20-24 in 10 µm.

Neidium bobmarshallensis has lanceolate valves, 14-18 µm wide. The central area is diagonal. Striae are also diagonal and number 13-15 in 10 µm. The proximal raphe ends are hooked in opposite directions.

Links & ID's

Index Nominum Algarum (INA)

California Academy of Sciences (CAS)

North American Diatom Ecological Database (NADED)

NADED ID:

Autecology Discussion

Besides three lakes in the Bob Marshall Wilderness of northwestern Montana, Neidium bobmarshallensis has been recorded from Logging Lake in nearby Glacier National Park. On the date the Logging Lake sample was collected, pH measured 7.78 and specific conductance measured 43. This species was also reported (as N. kozlowi var. elliptica) from a small pond in the Brooks Range of Alaska (Foged 1981).